Download Physics as a Journey Through Scales

Renate Loll, Institute for Theoretical Physics,
Utrecht University:
Physics as a Journey Through Scales from the very large to the very small
Lecture for Master Class students,
Utrecht, 29 Oct 2010
Things to take away from this lecture
The universe stretches over a vast range of length scales each scale is associated with particular physical phenomena.
Different parts of physical theory try to describe what
happens at different length scales, and formulate physical laws.
“Reductionism” has been a very fruitful way of explaining the
physical world - understanding the “big” from the “small”.
“Fundamental Physics” deals with the very small (quantum
physics of elementary particles) and the extremely small
(quantum physics of space and time).
Let’s get started by increasing your
“scale awareness”.
The easiest way of measuring extreme length
scales is in terms of “powers of ten”:
for example,
6
10
m = 1000000 m = 1000 km
102 m = 100 m
100 m = 1 m
10-1 m = 0.1 m
-3
10 m = 0.001 m = 1 mm
10-8 m = 0.00000001 m
etc.
Physical scales (in meters, measured in powers of ten)
visible universe
10-35
1026
1021
physics of particle
accelerators: quarks, gluons
spiral galaxy
10-19
107
10-10
atom
Earth
100
us
Our journey from the very large
to the extremely small begins ...
1026 meters = 100 yottameters
The Observable Universe
1025 meters = 10 yottameters
Largest Structures in the Universe
1024 meters = 1 yottameter
Clusters of Galaxies
1023 meters = 100 zettameters
The Virgo Cluster
1022 meters = 10 zettameters
The Local Group
1021 meters = 1 zettameter
The Milky Way
1020 meters = 100 exameters
Our Spiral Arm
1019 meters = 10 exameters
The Stars of the Orion Arm
1018 meters = 1 exameter
Stars within 50 Light Years
1017 meters = 100 petameters
The Nearest Stars
1016 meters = 10 petameters
The Oort Cloud
1015 meters = 1 petameter
Sol
1014 meters = 100 terameters
Our Sun and a few Rocks
1013 meters = 10 terameters
The Solar System
1012 meters = 1 terameter
Within the Orbit of Jupiter
1011 meters = 100 gigameters
Venus, Earth and Mars
1010 meters = 10 gigameters
Four Days in July
109 meters = 1 gigameter
Earth and Moon
108 meters = 100 megameters
Earth
107 meters = 10 megameters
North and Central America
106 meters = 1 megameter
California
105 meters = 100 kilometers
The San Francisco Bay Area
104 meters = 10 kilometers
San Francisco
103 meters = 1 kilometer
Golden Gate Park
102 meters = 100 meters
Japanese Tea Garden
101 meters = 10 meters
A Pond with Lily Pads
100 meters = 1 meter
The One-Meter Square
100 meters = 1 meter
The One-Meter Square
10-1 meters = 10 centimeters
A Lily and a Bee
10-2 meters = 1 centimeters
A Bee’s Head
10-3 meters = 1 millimeter
A Bee’s Eye
10-4 meters = 100 micrometers
Pollen
10-5 meters = 10 micrometers
Bacterium
10-6 meters = 1 micrometer
Virus on a Bacterium
10-7 meters = 100 nanometers
A Virus
10-8 meters = 10 nanometers
DNA within a Virus
10-9 meters = 1 nanometer
The Structure of DNA
10-10 meters = 100 picometers
Carbon’s Outer Shell
10-11 meters = 10 picometers
The Inner Electron Cloud
10-12 meters = 1 picometer
Within the Electron Cloud
10-13 meters = 100 femtometers
The Nucleus
10-14 meters = 10 femtometers
The Carbon Nucleus
10-15 meters = 1 femtometer
A Proton
10-16 meters = 100 attometers
Inside the Proton
10-17 meters = 10 attometers
Quarks and Gluons
10-18 meters = 1 attometer
Within the Reach of the new Particle Accelerator LHC
Another 16(!) orders of magnitude below:
10-35 meters - The Planck Scale
What is in the empty space between the elementary particles?
Physical scales (in meters, measured in powers of ten)
visible universe
10-35
1026
what happens at the
Planck
scale
!
GN !
!Pl =
c3 ?
1021
physics of particle
accelerators: quarks, gluons
spiral galaxy
10-19
107
10-10
atom
Earth
100
us
What we still want to understand:
• high-energy theorists are not just interested in the behaviour of
matter and particles, but also in the structure of the “empty”
space in between
• modern quantum field theory gives us a very different picture of
empty space (the so-called “vacuum”)
• one big challenge is still how to combine the classical theory of
general relativity with the quantum nature of the other three
fundamental interactions (electro-magnetic, weak and strong).
• such a theory of quantum gravity will describe the structure of
the vacuum at the very smallest scale, the Planck scale
The End
Lecture for Master Class students,
Utrecht, 29 Oct 2010